Undercarriage for a telescopic frame

ABSTRACT

A telescopic undercarriage for raising and lowering a frame. The undercarriage includes a base section having a pair of parallel base legs extending from a first end to a second end of the base section, the base section including a first plurality of braces extending between respective upper surfaces of the base legs and a second plurality of braces extending between respective lower surfaces of the base legs, the base legs, first plurality of braces and second plurality of braces collectively providing an elongate central base section passage. The undercarriage also includes an extendable section slidably disposed within the base section passage and having opposed legs, a drive system for extending and retracting the extendable section relative to the base section.

This is a Continuation-in-Part of application Ser. No. 11/776,714,allowed Aug. 6, 2010.

BACKGROUND

Embodiments of the present invention relate to a part for telescopicframes, namely an undercarriage for a telescopic frame.

Telescopic frames are often used in telescopic stackers that are used tomove materials from one location to another.

Telescopic conveyor belts have seen use in heavy industries, such as theaggregate industry, where mobile conveyors are used to constructnon-segregated stock piles of aggregate materials. Telescopic stackersor conveyor belts used in the aggregate industry are quite large, and inorder to support telescopic conveyor systems of increasing size, anundercarriage must be made of ever stronger materials. An example of atelescopic stacker can be seen in U.S. Pat. No. 6,056,252.

SUMMARY OF THE INVENTION

According to one aspect of the present invention, there is provided atelescopic undercarriage for raising and lowering a frame, theimprovement comprising:

an extendable section telescopically mounted within a base sectionpassage for movement from the base section between retracted andextended positions, and having opposed base legs, each base leg definingan elongate open-sided base leg channel facing the other base leg;

a hydraulic drive system connected to the base section and theextendable section for extending the extendable section from the secondend of the base section, the hydraulic drive system including a firsthydraulic drive cylinder driving a first piston and a secondspaced-apart hydraulic drive cylinder driving a second piston, each ofthe first and second hydraulic drive cylinders being mounted solelywithin one of the base leg channels; and

the hydraulic drive cylinder being mounted within the other of the baseleg channels and the first and second pistons mounted within the otherof the extendable section legs such that when the extendable section isextended, the pistons and drive cylinder serve as reinforcement.

In another preferred embodiment of the present invention, the extendablesection of the undercarriage is retractable within the base section to atransport position and extended to a plurality of use positions, theundercarriage including a releasable mechanical stopper mounted to thebase section and having a contact portion for engaging the extendablesection to prevent retraction of the extendable section fully to thetransport position.

In a further preferred embodiment of the present invention, theundercarriage, in combination with a radial stacker wherein a first endof the base section is connected to a base support frame of the radialstacker and an extendable end of the extendable section is connected toa telescopic conveyor belt for raising and lowering the telescopicconveyor belt.

In yet another preferred embodiment of the present invention, the baselegs of the undercarriage each have a U-shaped cross-section.

In another preferred embodiment of the present invention, the hydraulicdrive system includes a first hydraulic cylinder driving a first pistonand a second hydraulic cylinder driving a second piston, the firsthydraulic drive cylinder being mounted within one of the base legchannels and the first piston being mounted within one of the extendablesection legs, the second hydraulic cylinder being mounted within theother of the base leg channels and the second piston being mountedwithin the other of the extendable section legs the pistons and theirmountings serving to reinforce the extendable legs.

In a further preferred embodiment of the present invention, theextendable section of the undercarriage can be retracted within the basesection passage to a transport position and extended to a plurality ofuse positions, the undercarriage including a releasable mechanicalstopper mounted to the base section and having a contact portion forengaging the extendable section to prevent retraction of the extendablesection fully to the transport position.

In a preferred embodiment of the present invention, the telescopicundercarriage supports a conveyor belt system for moving aggregate.

Another embodiment is a telescopic undercarriage for raising andlowering a frame. The undercarriage includes a base section having apair of parallel base legs extending from a first end to a second end ofthe base section, the base section including a first plurality of bracesextending between respective upper surfaces of the base legs and asecond plurality of braces extending between respective lower surfacesof the base legs, the base legs, first plurality of braces and secondplurality of braces collectively providing an elongate central basesection passage. The undercarriage also includes an extendable sectionslidably disposed within the base section passage and having opposedlegs, a drive system for extending and retracting the extendable sectionrelative to the base section.

Another embodiment is a telescopic undercarriage for raising andlowering a frame, comprising: a base section having a pair of parallelbase legs extending from a first end to a second end of the basesection, each base leg defining an elongate open-sided channel facingthe other base leg, the base section including a first plurality ofbraces extending between respective upper surfaces of the base legs anda second plurality of braces extending between respective lower surfacesof the base legs, wherein the base legs, first plurality of braces andsecond plurality of braces collectively define an elongate base sectionpassage; and an extendable section telescopically mounted within thebase section passage for movement from the second end of the basesection between retracted and extended positions and having opposed legsconnected by a third plurality of braces extending therebetween, each ofthe opposed legs being slidably received within a corresponding one ofthe base leg channels.

Another embodiment is an undercarriage for raising and lowering atelescopic frame that has a first end pivotally connected to a supportframe, the undercarriage comprising: a base section having a pair ofparallel base legs extending from a first end to a second end of thebase section, each base leg defining an elongate open-sided channelfacing the other base leg, the base section including a first pluralityof braces extending between respective upper surfaces of the base legsand a second plurality of braces extending between respective lowersurfaces of the base legs, wherein the base legs, first plurality ofbraces and second plurality of braces collectively define an elongatebase section passage, the first end of the base section being pivotallymounted to the support frame at a location spaced apart from the firstend of the telescopic frame; and an extendable section telescopicallymounted within the base section passage for movement from the second endof the base section between retracted and extended positions and havingopposed legs connected by a third plurality of braces extendingtherebetween, each of the opposed legs being slidably received within acorresponding one of the base leg channels, the extendable sectionhaving an extending end connected to the telescopic frame.

Another embodiment is an undercarriage for a telescopic frame, theundercarriage being connected to the telescopic frame for raising andlowering an end thereof, the frame comprising: a base section havingopposed inward-opening u-shaped legs having first ends pivotallyconnected to the horizontal frame, the u-shaped legs connected by aplurality of spaced apart braces extending from a top or bottom surfaceof a u-shaped leg to a corresponding top or bottom surface of theopposed u-shaped leg forming a passage; an extendable section disposedwithin the passage having opposed tubular legs with first ends pivotallyconnected to the telescopic frame and each tubular leg slidably receivedwithin a corresponding u-shaped leg wherein the opposed tubular legs areconnected by a plurality of spaced apart cross-braces; and a hydraulicdrive system for extending and retracting the extendable sectionrelative to the drive section.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other advantages of the invention will become apparent uponreading the following detailed description and upon referring to thedrawings in which:

FIG. 1 is a side view of a telescopic conveyor system illustrating anenvironment in which the present invention may be used with anextendable frame in a retracted position;

FIG. 2 is a perspective view illustrating the telescopic conveyor systemof FIG. 1 with the extendable frame in an extended position.

FIG. 3 is a top view of an undercarriage for the telescopic conveyorsystem in an extended position;

FIG. 4 is a side view of the undercarriage of FIG. 3;

FIG. 5 is cross-sectional view of the undercarriage of FIG. 3 takenalong line V-V of FIG. 3;

FIG. 6 is a perspective view of the undercarriage of FIG. 3;

FIG. 7 is a cross-sectional view of the undercarriage of FIG. 3 takenalong line VII-VII of FIG. 3;

FIG. 8 is a top view of the undercarriage of FIG. 3 in a retractedposition;

FIG. 9 is a side view of the undercarriage of FIG. 8;

FIG. 10 is cross-sectional view of the undercarriage of FIG. 9 takenalong line X-X of FIG. 9;

FIG. 11 is a perspective view of the undercarriage of FIG. 9;

FIG. 12 is a cross-sectional view of the undercarriage of FIG. 9 takenalong lines XII-XII of FIG. 9;

FIG. 13 is a perspective view of the undercarriage of FIG. 3 inpartially extended position with a stopper inserted;

FIG. 13A is an expanded view of the portion of FIG. 13 indicated bycircle 13A.

FIG. 14 is a cross-sectional view of the inserted stopper taken alongline XIV-XIV in FIG. 13; and

FIG. 15 is a side view of a radial stacker with the undercarriage ofFIG. 3 in a completely retracted position for travel; and;

FIG. 16 is a side view of the radial stacker with the undercarriage inan extended use position.

While the invention will be described in conjunction with theillustrated embodiments, it will be understood that it is not intendedto limit the invention to such embodiments. On the contrary, it isintended to cover all alternatives, modifications and equivalents as maybe included within the spirit and scope of the invention as defined bythe appended claims.

DESCRIPTION OF EXAMPLE EMBODIMENTS

In the following description, similar features in the drawings have beengiven identical reference numerals where appropriate. All dimensionsdescribed herein are intended solely to illustrate an embodiment. Thesedimensions are not intended to limit the scope of the invention that maydepart from these dimensions.

Undercarriages are often used to raise and lower movable structures suchas extendable frames used for conveyor belts and radial stackers.Typical undercarriages include a base portion with a lower end fixed toa horizontal frame and an extendable portion with an upper end fixed toan upper end of a movable frame such as a conveyor belt frame. Ahydraulic drive cylinder including a cylinder mounted to the baseportion and a piston mounted to the extendable portion is used forextending and retracting the extendable portion. A debris guard mayextend along an upper surface of the piston to deflect aggregate debrisfrom the conveyor belt falling onto the piston. Angle iron cross bracesare used to strengthen the undercarriage. However, the relativeconfiguration of the pistons, base portions and extendable portionsleave a large length of the extendible portion without cross braces.This places a structural limitation on the size of the undercarriage andconsequently the size of the stacker (or other frame supported by theundercarriage). In at least some configurations, example embodiments ofan undercarriage as described below are designed to support a telescopicstacker that can handle a higher capacity (tons per hour [TPH]) andwhich has a larger overall dimensions than typical stackers, resultingin a stacker that may create a larger stock pile and still be highwayportable.

Referring to FIGS. 1 and 2, there is shown an example of a telescopicconveyor belt system, which as shown is a radial stacker 10,demonstrating an environment in which example embodiments of anundercarriage 36 may operate. The stacker 10 includes a telescopic frame11 which has an elongate base frame 12 and an elongate extendable frame14. The extendable frame 14 is telescopically mounted for reciprocalmovement in and out of the base frame 12. FIG. 1 illustrates theconveyor belt system 10 with the extendable frame 14 in a retractedposition and FIG. 2 illustrates the conveyor belt system 10 with theextendable frame 14 in a fully extended position.

The conveyor belt system 10 includes a first conveyor belt 24, which ismounted on the base frame 12, and a second conveyor belt 26, which ismounted on the extendable frame 14. As best seen in FIG. 2, the firstconveyor belt 24 is mounted such that its load carrying surface islocated above upper support rails 16 of the base frame 12, and thesecond conveyor belt 26 is mounted such that its load carrying surfaceis located below the upper support rails 20 of the extendable frame 14.This configuration provides the necessary clearance for retracting theextendible frame 14 within the base frame 12. Conveyor belts 24 and 26are mounted on their respective frames for movement in a conventionalmanner, and when in operation serve to move a load such as aggregatefrom a feed end 28 of the conveyor system, located at the lower end ofthe base frame 12, to a discharge end 30 of the conveyor system, locatedat an upper end of the extendable frame 14. The conveyor belt system 10has an actuator system for extending and retracting the extendablesection 14.

The telescopic frame 11 of the conveyor belt system 10 is mounted on asupport frame 32, such that telescopic frame 11 can be raised andlowered and also transported from place to place. Support frame 32includes a horizontal frame 34, to which the base frame 12 is pivotallymounted in the vicinity of its feed end 28. An undercarriage 36 isprovided for elevating and lowering the telescopic frame 11. Theundercarriage 36 is pivotally attached at its lower end 18 to thehorizontal frame 34 and at its upper end 22 to base frame 12. Usually,undercarriage 36 is elevated and lowered by a hydraulic piston assembly.The maximum load bearing capability of undercarriage 36 constrains theheight, and length that telescopic frame 11 may extend. The supportframe 32 may include wheel assemblies 38 which can be rotated about thehorizontal frame 34 between a use position as shown in FIGS. 1 and 2,and a transport position (FIG. 15). In the transport position, the wheelassemblies 38 extend parallel to the longitudinal axis of the telescopicframe 11, and permit the conveyor belt systems 10 to be towed from placeto place (with the extendable frame 14 in a fully retracted position,and the telescopic frame 11 in a fully lowered position). Thus theconveyor belt system 10 may be a portable, telescopic, radial conveyorbelt system which can be used for a number of applications, includingforming non-segregated piles of aggregate.

The present disclosure is particularly concerned with the configurationof telescopic undercarriage 36, which is used to raise and lower theentire telescopic frame 11, which is shown in FIGS. 3 to 7 in anextended position and in FIGS. 8 to 12 in a retracted position. Althoughthe telescopic undercarriage 36 is described in the context of a radialstacker, its application is not limited to a radial stacker and in otherexample embodiments can be used in combination with other frames orstructures that need to be raised and lowered.

In undercarriage 36, as best indicated in FIGS. 3 and 6, the basesection 40 has a lower end 18 that attaches to horizontal frame 34 andthe extendible section 42 has an upper end 22 that attaches to theconveyer frame 12. Undercarriage 36 is configured so that cross-braces44 extend between legs 46 of the extendable section 42 substantially theentire length of the extendable section 42. Cross-braces 48 extendbetween legs 50 of the base 40 substantially the entire length of thebase section 40. Such a configuration provides improved strength andrigidity to the undercarriage 36, allowing for larger undercarriages andhence larger radial stackers to be manufactured. The cross-braces 44 and48 may be, for example, elongate cylindrical members or elongate angleiron members.

In order to permit for bracing all the way along the lengths of theextendable section 42 and base section 40 the following configuration isprovided. The extendable section 42 includes a pair of tubular, parallellegs 46. In the illustrated embodiment, tubular legs 46 each have squarecross-sectional area, however the legs could alternatively have acircular or other type of multi-sided configuration. As shown in FIGS. 5and 10, a respective drive piston 54 extends inside and is securedwithin each of the tubular legs 46. The tubular legs 46 (See FIGS. 3, 7and 12 for example) have opposed inner facing surfaces 52 between whichcross-braces 44 extend to interconnect the legs 46. As indicated inFIGS. 3 and 8, some braces 44 include braces 45 that extend at rightangles between the legs 46 and angled braces 47 that each extend from amid-point of a right angle brace 45 to a respective leg 46. Othercross-bracing configurations between legs 46 are possible. The tubularconfiguration of legs 46 allows for cross-bracing 44 between the innersurfaces of legs 46, and protects the internally located pistons 54 fromdebris. As shown in FIGS. 5 and 10, each piston 54 is anchored at oneend 59 to an elongate piston anchor 56 that is located in each leg 46.In each leg 46, the piston anchor 56 is spaced from the interior wallsof the leg 46 by mounting plates 57 to keep the piston 54 centered.

The base section 40 includes opposed legs 50 that are connected by crossbraces 48. The opposed legs 50 each have a U-shaped cross-section, withthe open-sides of the U facing each other and defining opposed channelsso as to not interfere with the cross-bracing 44 of extendable section42 as the legs 46 telescope in and out of legs 50 of base section 40.Furthermore, the cross braces 48 are located on top and bottom surfacesof the opposed base section legs 50, thereby providing a passage 58between base section legs 50 and base section cross braces 48 for theextendable section 42 to telescope into and out of. As best seen inFIGS. 6 and 11, in one example embodiment, the base section cross-bracesinclude braces 49 that extend at right angles between the upper andlower surfaces of the base legs 50, and angled braces 51 that are eachconnected at one end to a mid-point of right angle brace 49 and atanother end to one of the base section legs 50. Other cross-bracingconfigurations are possible. As best seen in FIGS. 5 and 10, a hydraulicdrive cylinder 80 is secured in the U-shaped channel provided in eachbase leg 50 for driving the piston 54 that is secured to the extendablesection leg 56 in order to extend and retract the extendable section 42out of and into the passage 58. When the extendable section 42 isretracted, its tubular legs 46 each telescope partially over arespective one of the drive cylinders 80. Thus, when the undercarriage36 is in a retracted position, a substantial portion of a piston 54 isreceived within a respective drive cylinder 80, which itself issubstantially received within a respective extendable section tubularleg 46, which is substantially received within a respective one of thebase legs 50.

It is contemplated that the cross braces 44 and 48 may be configured inany manner to provide structural support, provided that cross braces 48connect respective top and bottom surfaces of the base section legs 50,and that cross braces 44 are configured to be disposed within thepassage 58.

Turning now to FIGS. 13 to 16, in one example embodiment removablestoppers 60 can be placed in the lower ends of the base legs 50 toprovide a mechanical barrier that prevents extendable legs 42 from beingfully retracted into the base legs 50 during use of the undercarriage36. More particularly, FIG. 15 shows the stacker 10 in a travel positionin which the extendable section 42 of undercarriage 36 is fullyretracted in the base section 36 to minimize the size of the stacker 10for transport purposes, and FIG. 16 shows the stacker 10 with theundercarriage 36 in a fully extended use position. During use of thestacker 10, the extendable section 42 will typically never be in itsfully retracted travel position, but rather will always be in at least apartially extended state. As will be appreciated from FIGS. 15 and 16,the forces applied to the hydraulic system that powers the undercarriage36 will be greater when the extendable section is retracted. In oneexample embodiment, removable stoppers 60 are used to alleviate thestresses placed on hydraulic system used to extend and retract theundercarriage.

For example, as shown in FIGS. 13, 13A and 14, in one particularembodiment a rectangular slot 64 is provided near a lower end of each ofthe base legs 50 for receiving a respective removable stopper 60. Theslots 64 are positioned so that when stoppers 60 are in place, they willengage the lower ends of the legs 44 of extendible section 42 as theextendable section is retracted into the base section 40 such that theextendable section 42 can only be partially retracted into the basesection 40 and is prevented from sliding to a completely retractedposition. In one example embodiment, the slots 64 are positioned so thatwhen stoppers 60 are in place they engage the extendable section 42 whenthe extendable section 42 is in partially retracted position thatcorresponds to the minimum amount of extension of the undercarriage 36required during use of the stacker 10. Thus, when the stoppers 60 are inplace and engaging the lower ends of legs 44 of the extendable section42, the stoppers will take at least some of the load off of thehydraulic system when the extendable section 42 is in its most retracteduse position (shown in FIG. 13, which is not as retracted as the travelposition shown on FIG. 15). In some applications, such a configurationcan extend the life of the hydraulic system and/or allow a smallerhydraulic system to be employed and/or lighter undercarriage to be usedthan could otherwise be used in the absence of stoppers 60.

As best shown in FIG. 14, in at least one example embodiment, the slot64 formed in a base leg 50 includes aligned upper opening 70 and loweropening 72. The stopper 60 in the illustrated embodiment takes the formof a removable pin having a first planer rectangular portion 66 forinsertion through the upper and lower openings 70, 72, and portion 66provides the mechanical barrier for engaging the extendable leg 44. Anexternal stopper portion 68 extends substantially at a right angle fromthe insertable portion 66 for holding the stopper 60 in place and alsoproviding a handle for removing the stopper 60. In other embodiments,other forms of mechanical barriers could be used to implement thefunctionality of stopper 60.

When being transported, it is desirable that extendible section 42 befully inserted into base section 40 as shown on FIG. 15. Thus, stoppers60 are removed from slots 64 during transportation and then, when thetelescopic stacker 10 is to begin operation, extendable frame 14 iscompletely retracted, extendable section 42 is partially extended andstoppers 60 are placed in slots 64. In some example embodiments, thedesired maximum retracted use position may vary depending on theapplication, and accordingly in some configurations multiple slots canbe provided along base legs 50 to provide multiple positions forstoppers 60 so that the maximum retracted use position for undercarriage36 can be easily adjusted.

Although the above description has focused on the use of theundercarriage in the context of a telescopic frame for a conveyor beltassembly, it will be appreciated that the undercarriage could be usedwith frames used for other purposes.

Thus, it is apparent that there has been provided in accordance with theinvention an undercarriage that fully satisfies the aims and advantagesset forth above. While the invention has been described in conjunctionwith illustrated embodiments thereof, it is evident that manyalternatives, modifications and variations will be apparent to thoseskilled in the art in light of the foregoing description. Accordingly,it is intended to embrace all such alternatives, modifications andvariations as fall within the spirit and broad scope of the invention.

1. In a telescopic undercarriage for raising and lowering a frame, theimprovement comprising: an extendable section telescopically mountedwithin a base section passage for movement from the base section betweenretracted and extended positions, and having opposed base legs, eachbase leg defining an elongate open-sided base leg channel facing theother base leg; a hydraulic drive system connected to the base sectionand the extendable section for extending the extendable section from thesecond end of the base section, the hydraulic drive system including afirst hydraulic drive cylinder driving a first piston and a secondspaced-apart hydraulic drive cylinder driving a second piston, each ofthe first and second hydraulic drive cylinders being mounted solelywithin one of the base leg channels; and the hydraulic drive cylinderbeing mounted within the other of the base leg channels and the firstand second pistons mounted within the other of the extendable sectionlegs such that when the extendable section is extended, the pistons anddrive cylinder serve as reinforcement.
 2. The undercarriage according toclaim 1, wherein the extendable section is retractable within the basesection to a transport position and extended to a plurality of usepositions, the undercarriage including a releasable mechanical stoppermounted to the base section and having a contact portion for engagingthe extendable section to prevent retraction of the extendable sectionfully to the transport position.
 3. The undercarriage according to claim1, in combination with a radial stacker wherein a first end of the basesection is connected to a base support frame of the radial stacker andan extendable end of the extendable section is connected to a telescopicconveyor belt for raising and lowering the telescopic conveyor belt. 4.The undercarriage according to claim 1, wherein the base legs each havea U-shaped cross-section.
 5. The undercarriage according to claim 1,wherein the hydraulic drive system includes a first hydraulic cylinderdriving a first piston and a second hydraulic cylinder driving a secondpiston, the first hydraulic drive cylinder being mounted within one ofthe base leg channels and the first piston being mounted within one ofthe extendable section legs, the second hydraulic cylinder being mountedwithin the other of the base leg channels and the second piston beingmounted within the other of the extendable section legs the pistons andtheir mountings serving to reinforce the extendable legs.
 6. Theundercarriage according to claim 5, wherein the extendable section canbe retracted within the base section passage to a transport position andextended to a plurality of use positions, the undercarriage including areleasable mechanical stopper mounted to the base section and having acontact portion for engaging the extendable section to preventretraction of the extendable section fully to the transport position. 7.The undercarriage of claim 5, wherein the telescopic undercarriagesupports a conveyor belt system for moving aggregate.